phiopt: reorganize factoring/cselim-limited for phiopt

This is in preparation for adding factoring out loads
for phiopt were we want to loop over all 3 factoring
cases if one of them made a change so that a load elimination
might allow for a store elimination.

This moves the cs-elim limited loop into the factoring out
operation into the same loop.

Bootstrapped and tested on x86_64-linux-gnu.

gcc/ChangeLog:

	* tree-ssa-phiopt.cc (factor_out_all): New function.
	(pass_phiopt::execute): Call factor_out_all isntead
	of factor_out_conditional_operation and
	cond_if_else_store_replacement_limited.

Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>